The present invention relates to a silver halide photographic material and, in particular, to a silver halide photographic material of super-high contrast for use in photomechanical process.
An image-forming system which shows super high contrast photographic properties (in particular, with a xcex3 value of 10 or more) is required in the field of graphic arts to obtain good image reproduction of continuous tone by dot images or reproduction of line images.
An image-forming system has been desired which comprises developing a photographic material using a processing solution having excellent storage stability to provide super high contrast photographic properties. By way of example, a system has been proposed which comprises processing a surface latent image type silver halide photographic material containing a specific acylhydrazine compound with a developing solution containing 0.15 mol/liter or more of a sulfite preservative and having a pH value of from 11.0 to 12.3 to form a super high contrast negative image with a xcex3 value of more than 10 as disclosed in Pat. Nos. 4,166,742, 4,168,977, 4,221,857, 4,224,401, 4,243,739, 4,272,606, and 4,311,781. This novel image-forming system is characterized in that silver iodobromide or silver iodochlorobromide can be used in contrast to conventional super high contrast image-forming systems in which only silver chlorobromide having a high silver chloride content could be used. Furthermore, the system has a comparatively good storage stability because it can contain a large amount of a sulfite preservative as against the conventional lith developing solution which could use only a slight amount of a sulfite preservative.
High contrast materials containing two kinds of silver halide grains and hydrazine derivatives are disclosed in EP 0208514, JP-A-61-223734 and JP-A-63-46437 (the termxe2x80x9cJP-Axe2x80x9d as used herein means anxe2x80x9cunexamined published Japanese patent applicationxe2x80x9d).
A high contrast photographic material which contains a hydrazine derivative and is characterized in that the silver halide grains are spectrally sensitized in high concentration per surface area of the silver halide grain, as compared with other silver halide grains, is disclosed in the claims of JP-A-4-331951. Further, a high contrast photographic material containing silver halide grains spectrally sensitized with a non-desorptive sensitizing dye, silver halide grains not spectrally sensitized, and a hydrazine derivative is disclosed in the claims of Unexamined Published British Patent Application No. 9,407,599. In both cases, the presence of a hydrazine derivative contributes to the formation of a silver image in which spectrally sensitized light-sensitive grains and light-insensitive grains not spectrally sensitized are formed by imagewise exposure and development, further contributes to obtaining high sensitivity, saving sensitizing dyes while maintaining high concentration and improving the occurrence of residual color.
Although these photographic materials are excellent in processing stability, contrast and sensitivity, and exhibits less residual color, they have a drawback that exposure unevenness is caused when from 60 to 90% of half-tone image is outputted by an image setter.
An object of the present invention is to provide a silver halide photographic material which hardly causes exposure unevenness by an image setter, and a method for processing the same.
The above objects of the present invention have been accomplished by the following silver halide photographic material and a method for processing the same.
1) A silver halide photographic material comprising a support having provided thereon at least one light-sensitive silver halide emulsion layer and at least one light-insensitive hydrophilic colloid layer, wherein the at least one light-sensitive silver halide emulsion layer contains at least two kinds of silver halide emulsions having different speeds, the light-insensitive hydrophilic colloid layer contains at least one kind of light-insensitive silver halide grains, the silver halide emulsion layer or the light-insensitive hydrophilic colloid layer contains at least one kind of hydrazine derivative as a nucleating agent, and at least one kind of compound selected from the group consisting of an amine derivative, an onium salt, a disulfide derivative and a hydroxymethyl derivative as a nucleation accelerator.
2) The silver halide photographic material as described in the above item 1), wherein at least two kinds of silver halide emulsions having different speeds are contained in one and the same light-sensitive silver halide emulsion layer or in different light-sensitive silver halide emulsion layers.
3) The silver halide photographic material as described in the above item 2) , wherein the silver halide grains contained in at least two kinds of silver halide emulsions having different speeds have different grain sizes.
4) The silver halide photographic material as described in the above item 1), 2) or 3), wherein the silver bromide content of the light-insensitive silver halide grains is 50 mol % or more. 5) A method for processing a silver halide photographic material which comprises continuously development processing the silver halide photographic material described in the above item 1) , 2) 3) or 4), wherein the replenishing rate of a developing solution is 200 ml or less per m2 of the photographic material, the developing temperature is from 30xc2x0 C. to 40xc2x0 C. and the developing time is from 6 to 22 seconds.